ProMetric® I-SC: Combination Imaging Colorimeter/Spectrometer Solution

The ProMetric^® I-SC Solution from Radiant Vision Systems integrates the functions of a ProMetric I Imaging Colorimeter with a high-end spectrometer to offer a single platform for spectral data capture and precise, repeatable color measurement for various devices, testing environments, and over time.

Users can capture spectral and spatial measurement data at the same time with a single solution.

Repeatable and accurate CIE-matched measurements.

Continuous operation, such as completely automated data capture and system calibration.

Two Measurement Systems in One

The ProMetric I-SC Solution offers a single platform for quantifying spectral data, chromaticity (CIE xy and u‘v’), and luminance (cd/m²) to assess the appearance of light-emitting devices like illuminated components, displaysand light sources.

The ProMetric I-SC Solution utilizes a polarization-insensitive mirror to integrate the functions of a specially designed tristimulus imaging colorimeter (ProMetric I-series from Radiant) with a high-end spectroradiometer (CAS 140D from Instrument Systems GmbH).

This innovative design relies on patented technologydeveloped by Radiant Vision Systems (US Patent No 8482652). Integrating two systems into one solution, the ProMetric I-SC allows manufacturers to deploy full light and color measurement functions seamlessly and efficiently.

Image Credit: Radiant Vision Systems

Advantages of the ProMetric I Imaging Colorimeter

The ProMetric I-SC Solution leverages the benefits of Radiant’s ProMetric I Imaging Colorimeter for light and color measurement. ProMetric I systems provide first-in-class imaging performance for metrology applications and are purpose-built for manufacturing inspection to fulfill speed and precision demands from R&D to production.

The ProMetric I61 (61-megapixel) Imaging Colorimeter has the ability to capture a full device in a single image for fast and accurate measurement of all regions of interest — down to areas as small as a display subpixel.

The built-in tristimulus color filter wheel of the ProMetric I offers a system response intrinsically close to CIE color-matching functions. Here, each color channel of the system has a near-perfect alignment to the CIE response curves.

This enables the system to retain precision even when the device's colorshifts slightly from the initial calibration point, expanding the effectiveness of each system calibration.

ProMetric I also improves measurement speed, capturing the highest amount of data with the greatest precision per data point in under 2 seconds per full-color measurement.

Illustration of the innate spectral response of the ProMetric I Imaging Colorimeter for each color channel (dotted lines) as compared to the standard CIE color-matching functions (solid lines). Image Credit: Radiant Vision Systems

Furthermore, the ProMetric I-SC solution leverages the optical configurations of the ProMetric I-series imaging colorimeter to allow spectral and spatial measurements inside special contexts.

For instance, the ProMetric I-SC can use Radiant’s AR/VR Lens to capture measurement data from within virtual and augmented reality headsets, at the near-eye position.

Not only does this configuration allow spatialchromaticity, luminanceand defects to be detectedthroughout the angular field of view, it also positions the spectral measurement point within the headset to capture precise spectral data.

Highly Accurate Spectral Data

Spectral data is obtained by the ProMetric I-SC solution by capturing an image of the device under test with the help of the imaging colorimeter and directing light from a center point on the device through the fiber-optic cable to the spectrometer.

The spectrometer assesses individual wavelengths of the light beam ranging between 380 to 780 nm to offer a highly precise spectral measurement. This data is used to identify:

Color rendering index (CRI)

Correlated color temperature (CCT)

Spectral distribution

Spectral bandwidth [full-width half-maximum (FWHM)]

Dominant wavelength

Peak wavelength

Spectral values are quantified from a center point on the measurement image captured by the combined imaging colorimeter. In the context of an image, the proper coordinates of the spectral measurement can be derivedand employed for extremely precise positioning of this point compared to the device under test.

The spectral measurement point’s spatial position is output in x, y coordinates as well as angular degrees, for instance, for inspection inside AR or VR headsets.

Also, the measurement point and field of view of the connected spectrometer are displayed on the measurement image in software as a graphical element (rectangle or circle) for rapid contextual visualization.

Image Credit: Radiant Vision Systems

Spectral data can be utilized to define device output, track variations in emission spectraand assess devices against defined tolerances.

Spectral data can be stored, exportedor utilized as a reference to calibrate the connected imaging colorimeter’s response per CIE color-matching functions for new devices and device states (that is, a different-colored backlit component or display).

Field of view of the integrated spectrometer shown as a circle in the center of the measurement image in software, located at a defined x, y measurement point. Image Credit: Radiant Vision Systems

Engineered to Maximize Capability and Utility

Some applications require the abilities of both a spectrometer and an imaging system for device qualification — the spectrometer offering highly precise values of color rendering index (CRI), correlated color temperature (CCT), etc., andthe imaging system offering accurate chromaticity (CIE xy or u‘v’), luminance (cd/m²), and visual inspection for all points throughout an image.

If spectrometers and imaging systems are employed separately, manufacturers have to source and purchase both systems and can only apply one system at a time for measurement, necessitatingmultiple stations or processes.

In such cases, manual setup and data transfer could cause considerable downtime or introduce errors at any stage.

With the help of the ProMetric I-SC, Radiant provides the benefit of both systems’ abilities in one solution, thereby removing the trouble of purchasing multiple systems or learning individual platforms.

Furthermore, direct integration enables system functionality in the absence of manual intervention. Users can quantify spectral and spatial data at the same point on a source, track outputand directly apply color calibrations, without the need to move the equipment.

Integrating the abilities of both systems intothe ProMetric I-SC also improves the capability of the solution on the whole.

Through the context of measurement images, users can specify and view the location of the spectrometer’s spectral measurement point, which is not possible when utilizing a spectrometer separate from an imaging system.

And, since the spectrometer utilizes the imaging colorimeter’s optics, it can obtain spectral data in any area that is visible to the imager from the same comparative position and angle.

Image Credit: Radiant Vision Systems

Intuitive Software Interface and Data Visualization

The ProMetric I-SC Solution can be used with Radiant’s TrueTest™ Software and application-specific software modules for automated measurement, visual inspection, equipment controland communications

TrueTest provides the extensive range of Radiant’s display measurement ability and the potential to sequence tests for quick and automated assessment of all comparative display characteristics in just seconds.

From TrueTest, users calibrate the ProMetric I-SC on demand and set calibration operations to run with an automated software process. TrueTest interface consists of a special view to envision spectral data that has been captured by the connected spectrometer and match or output data points.

The spectral data window in TrueTest Software shows the CIE 1931 chromaticity coordinates and spectral plot for data captured by the ProMetric I-SC Solution’s integrated spectrometer. The above image plots the spectral data measured at the center of a white OLED display. Image Credit: Radiant Vision Systems

ProMetric I-SC Solution Key Features and Highlights

Combination imaging colorimeter or spectrometer for fast and precise color measurement.

High-speed measurement and communications to aid manufacturing demands.

Spectral measurement ability, data visualizationand output.

On-demand or automatic calibration, depending on user-defined settings in the software.

CIE-matched color filters for quantifying luminance and chromaticity values accurately correlated with human visual perception.

Compatibility with any TrueTest software package

Combined with a specially engineered ProMetric I61 Imaging Colorimeter (61-megapixel resolution).

User-friendly interface for viewing, applyingand exporting spectral and colorimetric measurement data.

Optionally applied with Radiant’s AR/VR Lens for in-headset calibration and measurement.